And I'm Renee Montagne. In Libya, what had looked like a day of triumph for rebels, turned grim yesterday. It was unclear how much progress rebels had actually made in taking the capitol Tripoli, and Moammar Gadhafi's son, Seif al-Islam, made a surprise appearance, then flashed the victory sign, after rebels claim to have captured him.

NPR's Lourdes Garcia-Navarro has spent the past few days in and around Tripoli. Let's begin by talking about Gadhafi's son. He was out and about in Tripoli last night, clearly free, not captured by rebels. What was going on there?

LOURDES GARCIA-NAVARRO: It's a fiasco, essentially, for the National Transitional Council, the rebel leadership that had announced that announced that they had caught Seif al-Islam, Gadhafi's heir apparent and the person who is essentially directing the fight against the rebels at this point. And so, he showed up in Bab al-Azizia, his father's sprawling compound in the center of Tripoli, and essentially spoke to journalists who are now holed up at the Rixos Hotel, and they were taken there. And he basically said that the rebels had been allowed into the city because they were setting a trap for them. And, that his father was well and still in Tripoli, as well. And basically, speaking very defiantly in the face of all this pressure that his father's government is under at the moment.

It's an extraordinary turn of events, you really can't overstate it. And I think it has given a real boost to the Gadhafi government, to have Seif al-Islam still at large and still feeling comfortable enough to be in his father's compound and take journalists on a tour of the city.

MONTAGNE: And what can you tell us about what's actually happening today?

GARCIA-NAVARRO: Today in Tripoli, we've seen the situation markedly deteriorate from even yesterday, and yesterday was particularly difficult. In Tripoli, there are raging gun battles taking place in several key areas. One of them is Green Square, the iconic square which had been a Gadhafi stronghold. The rebels briefly had taken it over Sunday night when they marched in, but their hold was tenuous, and today we're seeing fierce gun battles taking place there and also around Bab al-Azizia, Gadhafi's compound. There are huge explosions, we understand; fierce battles taking place. And the fighting has spread to neighborhoods across the city that were nominally under rebel control yesterday.

There are, we understand, street fights, essentially, taking place in many areas. And heavy weapons are being used in civilian areas. Yesterday we saw mortar rounds landing in residential compounds. So the situation is increasingly fragile inside Tripoli. There is no electricity, there is limited food, and people are hunkering down in their homes, frankly terrified to go out.

MONTAGNE: And Lourdes, we're getting reports that rebels are advancing toward the oil terminals in Ras Lanuf, that's in the east. What do you know about that?

GARCIA-NAVARRO: What we know is that the eastern front had been static for a long time. It took months to take the oil terminal of Brega. They finally managed to do that. The next place along that road is, indeed, Ras Lanuf, and we do understand that rebels are advancing along that front. Why that is key is that Ras Lanuf the last, sort of, large place before Gadhafi's stronghold of Surt. That is an area that is still very much under his control. There is speculation that Gadhafi, himself, may be there, although Seif al-Islam, Gadhafi's son, maintained that his father is in the capital, Tripoli. However, we really don't have any proof of that. But Surt is a very important front, they need to take that, as well. It lies in between Misrata and the east, and if they manage to take Surt, than the entire, sort of, east of the country, up to Misrata and beyond, will be in rebel hands.

MONTAGNE: Well, finally, at this moment in time, what does it look like? Who, in fact, does have control of Libya?

GARCIA-NAVARRO: Well, certainly rebels control vast swaths of territory, but the fight for the capital is the key battle. And, right now, it is raging. And it's really not clear which side is winning.